I'm using an RTL-SDR to receive Es'Hail 2. My chain is as follows in order:

  • 60 cm TV Satellite dish pointing 2 degrees off Es'Hail 2
  • Universal LNB (from TV company, not really a stable frequency). This LNB downconverts the satellite to the 739Mhz band.
  • Long RG6 coax run (involving a serious amount of adapters and sockets in order to feed to the correct room in my house). The run is about 20-25m
  • RTL-SDR bias-t module
  • RTL-SDR AM filter module
  • NESDR Smart RTL-SDL (inside metal case)
  • Raspberry Pi (running rtl_tcp)
  • Windows laptop running SDR#

The following is an image of my reception strength: enter image description here

As long as I use SDR#'s audio noise filtering DSP, reception isn't too bad as long as the people transmitting are using a good amount of power. Weaker stations are quite hard to hear. Due to the unstable LNB, I have to keep re-tuning, but that's ok for now.

At this stage, installing a new, or re-aligning my satellite dish isn't an option.

I would appreciate any help on any tips in order to improve this reception. The RTL-SDR has quite a high noise floor compared to the satellite signal. FWIW, the noise doesn't drop much even with the antenna removed, indicated that the noise is internal to the device.

My current train of thought is to add a LNA somewhere, but I'm not sure where. Given my LNB requires a 12v bias-t, I'm unsure i'd be able to install an LNA close to the dish, without have to move the bias-t injector even closer as well.


1 Answer 1


20-25 meters of RG-6 coaxial cable has significant loss at 739 MHz.

RG-11 coax has significantly lower loss than RG-6. Unless there is an issue with your LNA, I expect that replacing the RG-6 with RG-11 will give you the signal boost that you are looking for.

What you could do in lieu of replacing the coax is add a low-noise preamp right at the dish, to overcome the loss in the coax and improve the S/N ratio.

  • $\begingroup$ Thanks for the tip, I appreciate your help. However I don't think I have this option, although i could try it out temporarily. Reason being is that our house had RG6 put inside the walls when the house was built. Ironically, it also has Cat6 going round the house. I wonder if some sort of balun would let me send 739Mhz over Cat6... $\endgroup$
    – jt.retro
    Apr 6, 2019 at 21:46
  • $\begingroup$ @jt.retro A balun would not improve anything. It would only add additional loss. What you could do in lieu of replacing the coax is add a low-noise preamp right at the dish, to overcome the loss in the coax. A balun (BALanced to UNbalanced) is for converting from a balanced load to an unbalanced load. In your case, nothing is balanced, since coax is inherently unbalanced. $\endgroup$
    – Mike Waters
    Apr 6, 2019 at 21:59
  • $\begingroup$ I was think about something like that, however how would this work given I'm already sending 12V via a bias-t up the coax? I'm assuming an LNA would be about 5v or something. Thanks $\endgroup$
    – jt.retro
    Apr 6, 2019 at 22:03
  • $\begingroup$ Incidentally, my balun statement was in reference to using the Cat6, as Cat6 is a balanced line. I don't seriously think Cat6 would work well at all though. $\endgroup$
    – jt.retro
    Apr 6, 2019 at 22:06
  • $\begingroup$ @jt.retro Are you using CAT6 LAN cable, or RG-6 as you have already stated? $\endgroup$
    – Mike Waters
    Apr 6, 2019 at 22:08

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